The function of a chamber (pipe-chamber) feeder consists of the periodical alternate filling of the chambers with slurry at low pressure and of emptying them at high pressure. While performing this function, the closing appliances, especially valves or sliding valves have to be opened and closed in a certain sequence and at short time periods. This can be most advantageously performed in a manner as it is described in the Hungarian Patent Specifications No. 160 526. If in any of the chambers the flow of slurry is stopped by closing the corresponding closing appliances, said chamber is then pressurized, which is relatively time-consuming when known prior-art equipment is used. For pressurizing, i.e. for increasing the pressure in a closed chamber, only a limited amount of the water flow delivered by the water pump can be used, the amount required would not cause considerable changes in either the quantity or the pressure of the water delivered by said pump.
From the aforementioned it becomes obvious that with traditional equipment a long-lasting time consuming changeover not only results from the slow motion of the closing appliances, but also from the fact that the above mentioned pressurizing of the pipechambers is rather time-consumptive with the result being the output of the equipment is considerably reduced. In addition, the pump transferring slurry from the slurry-tank into the pipe-chambers is prevented from working during the long changeover period so that if large quantities of slurry continuosuly arrive, solid matter may deposit in the slurry tank that can lead to serious break-downs.